Telephone-exchange system



UNITED STATES PATENT OEEIcE.

JOSEPH E. PENN, 0E ELIZABETH, NEW JERSEY.

TELEPHONE-EXCHANGE SYSTEM.

SPECIFICATION forming part of Letters .P'atent No. 285,245, dated September 18, 1883.

Application filed June10,1880. (No model.)

roan whom it may concern:

Be it known that I, JOSEPH E. FENN, now of Elizabeth, in the county of. Union and State of New Jersey, formerly of Buffalo, county of Erie, State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systems and Apparatus, of which the following is a specification. I

My invention relates to that system of intercommunication known as the district or exchange telephone system, which consistsof a principal or central station or stations; united by means of separate radiating telegraph or telephone lines with a number of sub-stations, the organization being such that any two of the sub-stations may at a moments notice be placed in direct communication with j each other by the attendant at the central sta- 1 tion,who upon being notified to do so, unites the two lines leading to the respective substations, so that the persons at the two sta tions may converse directly with each other. The first part of my invention relates to the method of operating my improved system; and its object'is to enable either one of two sub-stations which have been connected together for conversation to actuate a visual or audible signal at the point of connection at the central station by reversing his own battery, and thus notifythe attendant to disconnect the wires and restore them to their normal position.

The next part of my invention relates to the organization of instrumentalities for attaining the object of the invention; and it consists in certain novel combinations and arrangements of elements, which combinations are specifically designated in the claims at the end of this specification. This part ,of my invention has for its' objects, first, to provide each independent line in atelephone-exchange system with a terminal battery, the like poles of all the batteries being normally directed toward the central station, so that when any two lines are coupled together their batteries will oppose and neutralize each other and no current will traverse the line to interfere with the working of the telephones, while either person may by reversing his battery transmit a telegraphic signal to his correspondent; second, to provide a signaling device, either audible or visual,'at the central station, operated by a helix or coil placed between the adjacent ends of each pair of lines, when the same are connected together, in combination with the hereinbefore-mentioned independent telephone-lines, terminal batteries, batteryreversing switches or keys, and commutator for connecting said lines together in pairs, the arrangement being such that the said signal ing device may be operated at will by the reversal of either of the terminal batteries.

The accompanying drawing is a diagram representing a district or exchange telephone system embodying my improvements. This system is represented in the drawing as consisting of a central station and four radiating lines extending therefrom to an equal number of substations, two of which are shown in the drawing for the sake of illustration.

At the central station I provide a series of spring-jacks, equal in number to the number of independent lines radiating from the sta' tion. In the drawingI have shown four, as at A, B, O, and D. The lines enter these spring-j acks and from thence are conducted to a series of re a -magnets having polarized 0r permanently-magnetic armatures R R R B, and thence to a series of break-keys or pressbuttons, is k k k, and finally asingle wire common to all which forms a connection withthe ground. In connection with the relays R B &c., I prefer to arrange an ordinary electro magnetic annunciator, H, having drops ab c d, and a signal-bell, h, the whole being operated by a local battery, L. The circuit from one pole of this battery, as shown by the dotted line, divides into branches, onebranch going to the contact-points of each relay, thence to the corresponding drop of the annunciator, which it controls by means of an electro-magnet. The branchers are then united again in a common circuit which traverses the electromagnet of the alarm-bell h, and then returns to the other pole of the local battery L.

In order to connect together any two independent lines, I provide two wedges, -w w, for insertion into the spring-j acks, each wedge having one of its faces insulated and its other face attached to a flexible conducting-wire, as at 12 and 13. These wires 12 and 13 are so arranged as to form a loop in which'is in- I position, is not inserted in the spring-j ack A cluded the signaling device a: I have shown a neutral or non-polarized relay as the apparatus which I prefer to use for this purpose, this being arranged to operate a single-drop annunciator, J, and bell j simultaneously by means of a local battery, Z, connected therewith in a well-known manner; but a galvanometer or simple magnetic needle deflected by a coil when the current is passing may in many cases be employed to serve the same purpose. I have shown the apparatus at two sub-stations, respectively designated as station A and D, remarking that the apparatus at sub-stations B and O is precisely similar, .so

that the description about to be given of station A is equally applicable to the others.

F is a battery, its poles being connected by means of wires 3 and 4 to the reversing key or switch P, of well-known construction. This switch is normally kept in the position shown in the figure, so that the ground-wire Z is connected with the negative pole of the battery through the key K and wire 2, while the positive pole of the battery is connected to the line through the wire 4:, and the reversingswitch connecting-screw 5, wire 6, alarm-bell G, wire 7, and switch S. The switch S is arranged in the ordinary manner, so that the circuit of the line 8 may be directed. either through the alarm-bell G or the telephone T, at the pleasure of the attendant. As all the stations have the like poles of their terminal batteries (in this instance the positive poles) toward the central office, the polarized tongues of the relays RR 8m, will be deflected away from their contactstops and all the branches of the annunciator-battery L will be open.

The operation of the apparatus is as follows: If, for example, the attendant at station A wishes to converse with the attendant at station D, he first sends a signal to the central office by momentarily reversing the terminal battery F, which is done by moving the handle of the reversing-key P to the right. The wedge 20, when the apparatus is in its normal as shown in the figure, and therefore the re versal throws over the tongue of the relay R, and thus exposes the letter A on the annunciator H and at the same time strikes the bell. h. The attendant at the central station, thus notified, will answer by pressing the button k, which will sound the bell G at station A,

and may thereupon inform himself what station communication is desired with, either by means of a preconcerted code of signals upon the bell h, or by inserting a telephone at tached to a wedge into the spring -jaek A and conversing with the attendant at station A. Having by either of these means ascertained that connection is to be made with station D, he calls that station by the key and inserts the wedges w and 20 into the springjacks A and D, and thus the two lines are placed in direct connection through i he relay 1*. As the terminal batteries E and E now have their like poles opposed to each other, there will be no current on the united lines and the relay 1* will remain unaffected. This condi' tion of the current, however, does not interfere in the least with the carrying on of conversation by means of the telephone between the stations A and D. In order, however, to prevent the absorption. and weakening of the telephonic vibrations by passing through the relay 1, I prefer to provide a condenser, O, of considerable capacity, the opposite poles of which are connected, respectively, to the wires 12 and 13, thus enabling the telephonic vibrations to be transmitted inductively around the relay. Vhen the two stations have finished their conversation, either one of them, by simply reversing his own terminal battery for a moment, gives a clearing-out signal to the attendant at the central station, for the two terminal batteries, thus being momentarily brought into coincidence with each other, pro duce a current which acts upon the relay 1*, causing it to operate the bell j and annunciator J.

It is obvious that the relay 9' and its attachments might in many instances be advantageously replaced by a simple coil and galvanometer-needle, which would stand at zero as long as the batteries were opposed to each other, but would be deflected whenever either of them were reversed.

It is not absolutely necessary that the re= lays R R, &c., should be provided with polarized armatures, although in general I prefor to have them thus arranged. The ordinary non-polarized relays may be successfully applied without otherwise changing the arrangement shown in the figure. These should of course be arranged to close the local circuit of battery L on their back contacts, so that a signal may be given by pressing the break -key K, as at station A.

I make no claim to the combination hereinbefore described, and shown in the accompanying drawing, 'of a line connecting two substations, and a signaling device located in said line, whereby the operator at the central office may be notified to disconnect the sub-station lines from each other upon the discontinuance of conversation between them.

I claim as my invention 1. In a telephone-exchange system, the combination of two independent lines having their terminal batteries normally reverse to each other, and a uniting wire or conductor, in which is placed an electro-magnetic coil for operating a visual or audible signal, whereby said visible or audible signal may be actuated by the reversal of either of the terminal bat teries.

2. The combination, substantially ashereinbefore set forth, of two or more independent lines radiating from a central station to different substations, terminal batteries, one for each line, having their like poles normally directed toward the central station, a switch or IIO commutator at the central station for coupling any two of said independent lines together, and a battery-reversing switch or key at each sub-station.

3. The combination, substantially as hereinbefore set forth, of two or more independent lines radiating from a central station, terminal batteries, one for each line, having their like poles normally directed toward the cen- 10 tral station, a switch or commutator forcoupling any two of said in dependent lin es together,

a visual or audible signal operated by a helix or coil placed between the adjacent ends of each pair of lines when the same are connected together, and a battery-reversing switch or I 5 

